In this assessor-blind randomised controlled trial, 140 cardiac surgery patients, recovering from sternotomy, will be assigned to 8 weeks of twice-weekly supervised CR exercise training commencing at either 2 weeks (early CR) or 6 weeks (usual care CR) post-surgery. Usual care exercise training will adhere to current UK recommendations. Participants in the early CR group will undertake a highly individualised 2–3 week programme of functional mobility, strength and cardiovascular exercise before progressing to a usual care CR programme. Outcomes will be assessed at baseline (inpatient), pre-CR (2 or 6 weeks post-surgery), post-CR (10 or 14 weeks post-surgery) and 12 months. The primary outcome will be change in 6 min walk distance. Secondary outcomes will include measures of functional fitness, quality of life and cost-effectiveness.

Ethics and dissemination

Recruitment commenced on July 2017 and will complete by December 2019. Results will be disseminated via national governing bodies, scientific meetings and peer-reviewed journals.